Parallel-ruler



(No Model.) 2 Sheets-Sheet 2. B. E. SAWYER.

PARALLEL RULER. No. 436,842. Patented Sept. 23, 1890.

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vBURNSIDF. E. SAWYER, OF ATHOL, MASSACHUSETTS.

PARALLEL-RULR. f

SPECIFICATION forming part of Letters Patent No. 436,842, datedSeptember 23, 1890.

Application filed J' une l1, 1890.

To all whom it may concern:

, Be it known that I, BURNsIDE E. SAWYER, of Athol, in the countj7 ofWorcester and State of Massachusetts, have invented certain new anduseful Improvements in Combined T- Squares and Protractors or Angles, ofwhich the following, taken in connection with the accompanying drawings,is a specification.

My invention relates to a combined T- square and protractor or angle;and it consists in certain novel features of construction, arrangement,and colnbination'of parts, which will be readily understood by referenceto the description of the drawings, and to the claims hereinafter given,and in which my invention is clearly pointed out.

Figure 1 of the drawings is a plan of a drawing-board, a T-square, and aprotractor or angle. Fig. 2 is a section through the beam and a portionof the tongue of the T-square and a small portion of the drawing-boardon line l l on Fig. 1. Fig. 3 is asection through the tongue of thesquare andthe head of the protractor or angle on line 2 2 on Fig. l.Fig. .tis a transverse section of the protractor-hcad on line 3 3 onFig. 3, and showing the parts at the right of said line in elevation.Fig. 5 is a similar view, the cutting-plane being on line 4 4 on Fig. 3.Fig. 6 is a section on line 5 5 on Fig. 3 and showing the parts at theleft of said line in elevation, and Figs. 7 and 8 are, respectively, anedge View and a plan of the gage-bar for setting the tongue of theprotractor or angle, and Fig. 9 is a plan of a modified form of thegage-bar.

In the drawings, A is the drawing-board, having formed in its uppersurface along the front side and one end the rectangular grooves c anda', respectively.

B is the tongue of the T-square, and C is the head, rigidly securedthereto in a position at right angles to the edge of said tongue.

D is a secondary head or guide-plate provided with a slot b to receivethe tongue B, and firmly secured on the inner end of the spindle or stemc, which in turn is mounted in a bearing in thehub or boss d, and hasfitted upon its threaded outer end the thumbnut e, as shown. The innerend of the thumbnut eis counterbored to form a chamber to receive oneend of the spring f, the opposite seraiN. 855,010. (No model.)

ber or recess formed in the outer end of the hub or boss cl, the tensionof said spring tending to move the supplemental head D toward the fixedhead C.

In using my improved T-square the head C is placed against the leftfhandend of the drawing-board A. Then by pressing upon the outer end of thethumb-nut e the secondary head or plate D-will be moved away from thehead C until its lower edge is over the groove a', into which it drops,when, if the pressure is removed from the end of the nut e, the spring freacts to force the plate D hard against the inner side of the rib a3with just sufficient force to insure the contact of the edge of the headC with the edge of theboard, while at the same time the square is freeto be moved along the board in a direction at right angles to the edgeof the tongue B.

E is the tongue of the protractor or angle, pivoted at g to a plate F,which has rigidly secured thereto the guide plate or head h, so as toproject below the under surface of said plate a distance about equal tothe thickness of the tongue B of Vthe T-square and has formed thereinthe slot f.

G is a secondary guide-plate or head provided with a rectangular slot toreceive the plate F, below which it projects to the same level asthehead 7e. The secondary guideplate or head G is firmly attached to oneend of the spindle or shank t', which is fitted to a bearing in the hubl-I, which is pivoted to the plate F at 7c, and is counterbored at itsouter end to form an annular chamber Z around said spindle for thereception of one end of the spiral spring m, the opposite end of whichfits into a corresponding recess in th'einner end of the milledthumb-nut an', screwed upon the outer end of the spindle vl, as shown inFig. 3..

The spring 'm serves to press the guideplate G toward the guide plate orhead h, and thus insure contact of both of said guide plates or headswith the edges of the tongue of the T-square when placed thereon, insubstantially the same manner as described in reference to the head ofthe T-square and the drawing-board.

A stud 'n is screwed into the plate F, upon Vwhich is mounted so as tobe movable verti- IOO cally thereon the semicircular boss or hub o,

in the flat vertical side of which is screwed the headed stud oas shownin Figs. 3, 4, and 5. The boss or hub o has placed between it and theplateF a spiral spring p,the tension of which tends to raise said hub,and the upper end of the stud a is threaded and has fitted thereon amilled thumb-nut p', by means of which and the spring p said boss 0 maybe adjusted vertically. A toothed feedwheel fr, having secured to itsside a ratchetwheel r of somewhat less diameter, is mounted upon thestud oso as to be revoluble thereon, the lowerl side of which wheelsproject into the slot f', so that the wheel r may come in contactwiththe paper on the drawing-board. The stud o also has loosely mountedthereon, contiguous to the ratchet-wheel r', the lever s, provided atits free end with the finger pad or button s', and having pivoted to itsside the pawl t in position to engage with the teeth of theratchet-wheel r', into contact with which it is pressed by the spring t.The free end of the lever sis moved upward by the spring u, (shown inFigs. l and 6,) its movement in said upward direction being limited bythe stop-pin u coming in contact with the upper end of the boss or hub0, (see Fig. 6,) and its movement in a downward direction is limited bythe stop-screw w, which is adjustable to vary the length of feed, asshown in Figs. 4, 5, and 6.

The tongue E of the protractor or angle is provided with perforations frand as a means of attaching to said tongue a graduated bar or arm formeasuring the angle of said tongue E relative to the tongue of theT-square.

For instruments which are not to be used for purposes of a protractorfor measuring all the degrees of angularity, but provided with thepivoted tongue E to be adj usted to ten, twenty, thirty, forty-five, andsixty degrees, I prefer to use the straight bar J, provided with asingle pin y, and having marked thereon the proper graduations for saidangles; but for instruments that are to be used for the purposes of aprotractor, I prefer to use the segmental bar J having two pins z z toit the holes w and having its convex edge beveled and graduated, asshown in Fig. 9. The bars or arms J and J are removed after measuring orgaging the angle.

The langle-tongue and its appendages will be found very useful insection-lining and tinting in lines, and the operation is as follows:

When not desired for ruling lines that are evenly spaced, the nntp is soadjusted that the spring p will raise the boss or hub 0 and stud o` settherein to such a height that the teeth of the wheel o' will not touchthe paper on the drawing-board. If, however, it is desired to use theinstrument for section-lining or laying an even tint in lines, the nut pis screwed down upon the boss or hub o until the teeth of the wheelrbearupon the paper. The screw stop -pin fw is adjusted to the proper heightto give the desired movement to the bevel-tongue at each depression ofthe lever s. The operator moves the angular portion of the instrumentalong the tongue of the square to bring the upper edge of the tongue orblade E to the position where he wants the iirst line, draws said line,depresses the lever s with the iinger of his left hand, draws anotherline, depresses said lever again, and so continues the operation tillthe surface to be lined is covered.

When horizontal lines are to be drawn, the tongue E, with its plate F,is removed from the square tongue.

A great advantage is obtained in the use of the T-square havingv thesecondary head and s.

its attachments by virtue of the fact that the head C is always heldfirmly against the edge ofthe drawing-board without special attentionbeing paid thereto by the draftsrnan. v

I claim--` 1. In combination with a T-square having a tongue or bladeand beam or head rigidly attached thereto, a secondary head or gageplate provided with a slot to receive the square tongue and projectingabove and below said tongue, a stem or shank attached at one end to saidsecondary head and having a male screw-thread at its other end, a hub orboss pivoted to the fixed head of said square kand provided with abearing for said spindle or shank, a nut on the outer end of said shank,and a spring constructed and arranged to move said secondary head towardthe fixed head. Y f

2. The combination of a drawing-board having a groove a or a in itsupper face, a T- square composed of the tongue B and head C, rigidlyconnected together, the secondary head or guide-plate D, the spindle c,the pivoted boss or hub cl, the thumb-nut e, and the spring f, allconstructed, arranged, and operating substantially as described.

3. In combination with a T-square having a tongue and head rigidlyattached together, the plate F, the head h, irmly secured to said plateF at right angles thereto7 the tongue E, pivoted to said plate F, theboss or hub H, pivotally connected to said plate F, the guideplate orsecondary head G, provided with the spindle t', mounted in a bearing inthe bossfor hub H, the nut m', and the spring m.

4. The combination, with a T-square, ofthe plate F, the fixed head h,the secondary head or guide-plate G, provided with the spindle or shankt', the pivoted hub H, the nut m', the' spring m, the tongue or blade E,pivoted'to the plate F by a clamping-screw and having formed therein aperforation at a point rej moved from its pivotal connection, and' agraduated gage bar or arm provided with a pin to engage the hole in saidblade andl adapted to locate and determine the angle of said bladerelative to the square-tongue.

5. In combination with the tongue of a T- square, the plate F, providedwith the openin g f and the head h, rigidly secured thereto,

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the boss or hub H, pivoted to said plate, the Secondary head orguide-plate G, provided with the spindle or stem i, mounted in a bearingin said boss H, the nut m', spring m, the spindle or stud n. set in saidplate F, the boss or hub o, mounted thereon, the spring` p, between saidboss and the plate F, the nut upon the upper end of the stud n, the studo', set in the boss o in a horizontal position, the toothed wheels fr'and o", mounted on seid stud o', the lever s, also mounted on the studo',

the pawl t, mounted on said lever in position to engage the teeth of thewheel r, the spring t', to tot upon said pawl, and the spring u forraising the free end of the lever s, substantially as described.

In testimony whereof I have signed my name to this speeioation, in thepresence of two subscribing witnesses, on this 7th day of June, A. D.1890.

BURNSIDE E. SAWYER. Witnesses:

HENRY I-I. KENDALL, N. C. LOMBARD.

